JP7149845B2 - air purifier - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air purifier using a photocatalyst.

Photocatalysts such as titanium oxide (TiO ₂ ) are activated when exposed to ultraviolet rays to produce a strong oxidation-reduction action, and harmful compounds such as nitrogen oxides (NO _x ) and sulfur oxides (SO _x ) and contaminants It exerts an action to effectively decompose such as. As an air purifying device using a photocatalyst, there is known one in which an ultraviolet lamp is housed in a housing having an air inlet and an air outlet, and a photocatalyst is arranged within the irradiation range of the ultraviolet rays generated by the ultraviolet lamp. (See Patent Document 1).

Japanese Patent Application Laid-Open No. 2003-220123

However, there is a problem that the removal performance of acetaldehyde is insufficient unless many black lights of fluorescent tubes are used to excite titanium oxide.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an air purifier capable of improving the performance of removing acetaldehyde.

In the present invention, a housing, a photocatalyst member disposed in the housing and containing titanium oxide, and a light emitting unit disposed in the housing for irradiating the photocatalyst member with ultraviolet light and including a plurality of LED elements and an activated carbon member disposed within the housing, and a fan for circulating air within the housing.

In the above air purifier, it is preferable that the activated carbon member is arranged downstream of the photocatalyst member in the air circulation direction.

ADVANTAGE OF THE INVENTION According to this invention, the removal performance of acetaldehyde can be improved.

FIG. 1 is a schematic cross-sectional explanatory view of an air cleaner showing a first embodiment of the present invention. FIG. 2 is a plan view of the LED light-emitting part mounting board, and shows the case of 13-series and 4-parallel. FIG. 3 is a partial cross-sectional view of a mounting substrate in which LED elements are mounted on a Cu substrate. FIG. 4 is a graph showing acetaldehyde removal performance. FIG. 5 is a schematic cross-sectional explanatory view of an air cleaner showing a modification. FIG. 6 is a graph showing the operating performance of the LED element, with the horizontal axis representing the forward current (mA) and the vertical axis representing the LED light output (mW). FIG. 7 is a schematic cross-sectional explanatory view of an air cleaner showing a second embodiment of the present invention. FIG. 8 is a graph showing acetaldehyde removal performance. FIG. 9 is a graph showing acetaldehyde removal performance.

1 to 3 show a first embodiment of the present invention, and FIG. 1 is a schematic cross-sectional explanatory view of an air cleaner.
As shown in FIG. 1, this air purification device 1 includes a rectangular parallelepiped housing 2, a ceramic foam 3 arranged in the housing 2 and coated with titanium oxide (TiO ₂ ), and a ceramic foam 3 arranged in the housing 2. A light emitting device 4 for irradiating the ceramic foam 3 with ultraviolet light, a fan 5 for circulating the air in the housing 2, and a filter 6 for removing air dust disposed in the housing 2. have.

The housing 2 is made of aluminum, for example, and has an intake port 2a and an exhaust port 2b. In this embodiment, the intake port 2a and the exhaust port 2b are provided on side surfaces facing each other. Inside the housing 2, a fan 5, a light emitting device 4, a ceramic foam 3, and a filter 6 are arranged in this order from the side of the air inlet 2a toward the air outlet 2b.

The housing 2 has a dimension of 20 cm in the direction of air flow, a dimension of 15 cm in a horizontal direction perpendicular thereto, and a dimension of 15 cm in the height direction. Here, the black light of the conventional fluorescent tube is long, and the dimension in the height direction of the conventional housing had to be at least 20 cm or more. Moreover, at present, a single black light is ineffective and a plurality of black lights are used. However, by using the light-emitting device 4 having a plurality of LED elements 43, the dimension of the housing in the height direction can be reduced to 15 cm or less.

In addition, the intake port 2a and the exhaust port 2b are each covered with an insect net 7 made of an antibacterial material. This prevents insects from entering the housing 2 by being attracted by the light from the light emitting device 4 .

The ceramic foam 3 as a photocatalyst member is made of alumina, for example, and has a three-dimensional network structure inside. The surface of the ceramic foam 3 is coated with titanium oxide particles as a photocatalyst. Titanium oxide is excitable by light with a wavelength of 410 nm or less, and purifies the air in the vicinity of the excited state.

The fan 5 sends out the air in the housing 2 from the side of the intake port 2a to the side of the exhaust port 2b when operating. The fan 5 may be of any type, and may be a propeller fan or a sirocco fan. Moreover, the filter 6 is provided so as to close the exhaust port 2a in the housing 2 .

The light-emitting device 4 as a light-emitting unit includes a housing 41 , a power supply board 44 arranged inside the housing 41 , a plurality of LED elements 43 mounted on a mounting board 42 at the top of the housing, and a power supply board 44 . and a wiring 45 for connecting to an external power supply (not shown) for supplying DC power. The housing 41 is made of ceramic, for example, and has an opening. The light emitting device 4 emits light from each LED element 43 through the opening of the housing 41 .

FIG. 2 is a plan view of the LED light-emitting part mounting board, and shows the case of 13-series and 4-parallel.
As shown in FIG. 2, the LED light-emitting mounting board 42 is formed in a square shape, and the respective LED elements 43 are aligned vertically and horizontally. The circuit pattern 423 has a pair of anode electrode 426 and cathode electrode 427 and supplies power to each LED element 43 . In this embodiment, four series connection portions 428 in which 13 LED elements 43 are arranged are connected in parallel, and a total of 52 LED elements 43 are used.

Specifically, each LED element 43 has a size of 350 μm×350 μm in plan view, and is mounted on the LED light emitting mounting substrate 42 at a mounting interval of 20 μm to 200 μm. By mounting the LED elements 43 at this mounting interval , a highly integrated structure of each LED element 43 is realized. The housing 41 may have any shape as long as it has a highly integrated structure of the LED elements 43. For example, the housing 41 may be in the shape of a halogen lamp.

FIG. 3 is a partial cross-sectional view of a mounting substrate in which LED elements are mounted on a Cu substrate.
As shown in FIG. 3, the LED light emitting mounting board 42 includes a substrate body 421 made of metal, an insulating layer 422 made of resin formed on the upper side of the substrate body 421, and a circuit made of metal formed on the upper side of the insulating layer 422. It has a pattern 423, a heat dissipation pattern 424, and a white resist layer 425 as a surface layer formed on the upper side of the insulating layer 422 and made of an insulating material. The substrate body 421 is made of copper, and is connected to the heat dissipation pattern 424 through the heat dissipation portion 422a made of metal through the insulating layer 422 . In this embodiment, the heat dissipation portion 422a and the heat dissipation pattern 424 are also made of copper. The insulating layer 422 is made of, for example, a polyimide resin, an epoxy resin, a liquid crystal polymer, or the like, and serves to insulate the circuit pattern 423 from the conductive substrate body 421 . The circuit pattern 423 is made of, for example, copper having a thin film of gold on its surface (upper surface), and is electrically connected to each LED element 43 by a wire 431 . The white resist layer 425 is made of, for example, an epoxy-based resin mixed with titanium oxide filler, and exhibits a white color.

Each LED element 43 has an InGaN-based light-emitting layer, for example, and emits ultraviolet light. In this embodiment, the peak wavelength of each LED element 43 is 405 nm. In this embodiment, each LED element 43 is of a face-up type and electrically connected to the circuit pattern 20 by a wire 60 .

In the air purifying device 1 configured as described above, the fan 5 is operated in a state where the ceramic foam 3 is irradiated with ultraviolet light from the light emitting device 4, so that the air taken in from the intake port 2a is removed from the ceramic foam 3. can be purified and discharged from the exhaust port 2b. Here, by using the LED element 43 that emits ultraviolet light as the light emitting device 4 and having a highly integrated and high output structure, it is possible to improve the acetaldehyde removal performance as compared with a black light using a fluorescent tube.

FIG. 4 is a graph showing acetaldehyde removal performance, with the horizontal axis representing time and the vertical axis representing acetaldehyde concentration. In examining the acetaldehyde removal performance, first, one using a black light using a fluorescent tube (hereinafter referred to as Comparative Example 1) and a light emitting device 4 using an LED element 43 with an aluminum-based mounting substrate 42 ( Below, Example A) is compared. Incidentally, in Comparative Example 1 and Example A, a propeller fan was used as the fan. In acquiring the data, the ultraviolet irradiation was started 30 minutes after the start and ended 210 minutes after the start. As shown in FIG. 4, in Example A, compared with Comparative Example 1, the acetaldehyde concentration during ultraviolet irradiation decreased. From this, it is understood that the acetaldehyde removal performance is improved by making the LED element 43 have a highly integrated and high output structure.

Next, Example A was compared with a mounting board 42 having a copper base (hereinafter referred to as Example B). Also in Example B, a propeller fan was used as the fan. As shown in FIG. 4, in Example B, compared with Example A, the acetaldehyde concentration during ultraviolet irradiation decreased. From this, it is understood that the acetaldehyde removal performance is further improved by using the copper base substrate as the mounting substrate 42 of the light emitting device 4 .

Next, Example B was compared with a sirocco fan as the fan 5 (hereinafter referred to as Example C). Also in Example C, a copper-based board was used as the mounting board 42 . As shown in FIG. 4, in Example C, compared with Example B, the acetaldehyde concentration during ultraviolet irradiation decreased. From this, it is understood that the acetaldehyde removal performance is further improved by using the sirocco fan as the fan 5 of the air cleaner 1 .

Next, Example C was compared with a device in which the housing 41 of the light emitting device 4 was removed and the power supply board 44 was exposed to the air as shown in FIG. 5 (hereinafter referred to as Example D). Also in Example D, a copper-based mounting board 42 was used, and a sirocco fan was used as the fan 5 . As shown in FIG. 4, in Example D, compared with Example C, the acetaldehyde concentration during ultraviolet irradiation decreased. It is understood from this that the acetaldehyde removal performance was further improved by not providing the housing 41 of the light emitting device 4 (by exposing the power supply board 44).

FIG. 6 is a graph showing the operating performance of the LED element, with the horizontal axis representing the forward current (mA) and the vertical axis representing the LED light output (mW).
As shown in FIG. 6, it is understood that the light output of the LED element 43 is improved in the order of Example A, Example B, Example C, and Example D. FIG. This is due to the improved heat dissipation of the LED. That is, when the mounting substrate 42 of the light emitting device 4 is a copper base substrate, the light output of the LED element 43 is improved more than when it is an aluminum base substrate, and when the fan 5 of the air purification device 1 is a sirocco fan, it is more than a propeller fan. The light output of the LED element 43 is improved, and the light output of the LED element 43 is improved as compared with the case where the housing 41 of the light emitting device 4 is not provided.

In the above embodiment, the LED element 43 having a peak wavelength of 405 nm is used, but the peak wavelength is not limited to this and may be 365 nm, for example.

In the above embodiment, the ceramic foam 3 coated with particles of titanium oxide is used, but if titanium oxide is included, a plastic material or a liquid such as water may be used instead of the ceramic foam 3. can also

FIG. 7 is a schematic cross-sectional explanatory view of an air cleaner showing a second embodiment of the present invention.
As shown in FIG. 7, this air purification device 101 includes a rectangular parallelepiped housing 102, a ceramic foam group 103 arranged in the housing 102 and coated with titanium oxide (TiO ₂ ), and It has a light emitting device 4 arranged to irradiate the ceramic foam group 103 with ultraviolet light, a fan 105 for circulating air in the housing 102, and an activated carbon filter 109 arranged in the housing 102. .

The housing 102 is made of aluminum, for example, and has an intake port 102a and an exhaust port (not shown). In this embodiment, the intake port 102a is provided on a predetermined side surface, and the exhaust port is provided on the other side surface. A filter (not shown) for removing dust in the air is provided near the exhaust port. In the housing 102, the light emitting device 4, the ceramic foam group 103, the activated carbon filter 109, and the fan 105 are arranged in this order in the horizontal direction from the inlet 102a side. In this embodiment, the fan 105 is a sirocco fan, which sucks air flowing in the axial direction of the fan and discharges it in the radial direction. Note that the light emitting device 4 has the same configuration as that of the first embodiment, and therefore will not be described in detail here.

In addition, the intake port 102a and the exhaust port are each covered with an insect net 7 made of an antibacterial material. This prevents insects from entering the housing 102 by being attracted by the light from the light emitting device 4 .

A ceramic foam group 103 as a photocatalyst member is configured by stacking a first ceramic foam 103a, a second ceramic foam 103b and a third ceramic foam 103c each having a predetermined thickness. Each ceramic foam 103a, 103b, 103c is made of alumina, for example, and has a three-dimensional network structure inside. In this embodiment, each ceramic foam 103a, 103b, 103c has a thickness of 10 mm to 15 mm. Both surfaces of each of the ceramic foams 103a, 103b, 103c are uneven to increase the surface area. The surface of each ceramic foam 103a, 103b, 103c is coated with titanium oxide particles as a photocatalyst. Titanium oxide is excitable by light with a wavelength of 410 nm or less, and purifies the air in the vicinity of the excited state. Plastic such as polyester may be used instead of ceramic as the photocatalyst member.

The activated carbon filter 109 is made of a porous material containing oxygen, hydrogen, calcium, etc. in addition to most of carbon, and allows many substances to be adsorbed in its fine pores. Since the surface has a non-polar property, it can selectively adsorb granular organic substances smaller than the pores, and can obtain a deodorizing effect. In this embodiment, the thickness of the activated carbon filter 109 is 5 mm to 30 mm.

In the air purifier 101 configured as described above, the fan 105 is operated in a state where the ceramic foam group 103 is irradiated with ultraviolet light from the light emitting device 4, so that the air taken in from the intake port 102a is removed from the ceramic foam group. Group 103 can be cleaned and exhausted through an exhaust port. In this embodiment, in addition to the ceramic foam group 103, the activated carbon filter 109 also purifies the air, so that the acetaldehyde removal performance can be dramatically improved.

In addition, in the present embodiment, a plurality of ceramic foams 103a, 103b, 103c are stacked, and unevenness is formed on both surfaces of each ceramic foam 103a, 103b, 103c to increase the surface area. Purification action can be improved.

In addition, in this embodiment, the activated carbon filter 109 is arranged downstream of the ceramic foam group 103 in the air flow direction, so that the air entering the activated carbon filter 109 is purified in advance by the ceramic foams 103a, 103b, and 103c. I can let you. Therefore, deterioration of the activated carbon filter 109 can be suppressed, and the purification performance of the activated carbon filter 109 can be maintained for a long period of time. In addition, since the excitation light emitted from the light emitting device 4 is blocked by the ceramic foams 103a, 103b, and 103c and is not directly incident on the activated carbon filter 109, deterioration of the activated carbon filter 109 can be suppressed also by this. can be done.

8 and 9 are graphs showing the acetaldehyde removal performance with the horizontal axis representing time and the vertical axis representing the acetaldehyde concentration. In examining the acetaldehyde removal performance, one using only the activated carbon filter of the first specification (hereinafter referred to as Comparative Example 2), one using only the activated carbon filter of the second specification (hereinafter referred to as Comparative Example 3), and ceramic foam A comparison was made between one using only the group (hereinafter, Example E) and one using the ceramic foam group with the addition of the activated carbon filter of the first specification (hereinafter, Example F). In Comparative Example 2, Comparative Example 3, Example E, and Example F, a sirocco fan was used as the fan. In Examples E and F, an aluminum base was used for the mounting substrate of the light emitting device using the LED element. In acquiring data, in Example E and Example F, ultraviolet irradiation was started immediately after the start. As shown in FIG. 8, in Comparative Examples 2 and 3 in which purification is performed only by the activated carbon filter, the concentration of acetaldehyde stops changing after a certain period of time. On the other hand, in Example E, in which purification is performed only with the ceramic foam group, the concentration of acetaldehyde decreases even after a certain period of time has passed. As shown in FIG. 9, in Example F, in which the group of ceramic foams to which an activated carbon filter is added is used for purification, the concentration of acetaldehyde is rapidly reduced immediately after the start compared with Comparative Examples 2, 3, and Example E. can be made

Although the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the scope of claims. Also, it should be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

INDUSTRIAL APPLICABILITY As described above, the air cleaner of the present invention can improve the acetaldehyde removal performance and is industrially useful.

Reference Signs List 1 air cleaner 2 housing 3 ceramic foam 4 light emitting device 5 fan 42 mounting substrate 43 LED element 101 air cleaner 102 housing 103 ceramic foam group 103a first ceramic foam 103b second ceramic foam 103c third ceramic foam 105 fan 109 activated carbon filter

Claims (2)

a housing;
a photocatalyst member disposed in the housing and containing titanium oxide;
a light emitting unit disposed in the housing, irradiating the photocatalyst member with ultraviolet light and including a plurality of LED elements;
an activated carbon member disposed within the housing;
a fan for circulating air in the housing,
The light emitting unit is arranged only upstream of the photocatalyst member with respect to the air circulation direction,
The light emitting unit has a mounting board on which the plurality of LED elements are mounted, and a power supply board connected to the upstream side of the mounting board,
The electric board is exposed within the housing ,
The small air purifying device , wherein the plurality of LED elements are aligned in the vertical direction and the horizontal direction at intervals of 20 μm to 200 μm and mounted on the mounting substrate . 2. The air purifier according to claim 1, wherein the activated carbon member is arranged downstream of the photocatalyst member in the air circulation direction.

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